5.3 ls motor
mp70 turbo
megasquirt
z06 cam

Car is blowing smoke from breather hoses on driver and passenger side, and under boost blowing oil out. Problem got worse throughout the day after a couple of pulls, the exhaust is now blowing white smoke out the back after a pull, but after sitting for an hour I cranked it up again and it was not smoking. I think I am getting excessive oil through the turbo and also through my breather tubes under boost.

Plz help if you can. I am worried that I may have a blown head gasket, and extreme blow by

 

Sounds like a blown head gasket. Do a compression test and see what you come up w/. Check your oil and coolant for contamination too.

 

Thanks, will give it a try. I heard boost on these old j-yard motors lead to head gasket issues. Just getting the car driveable, so I figured I would have problems along the way.

 

What should I do before and after removing the heads? what gaskets, bolts, etch should I use. Thanks

 

If your only doing a head re/re use arp studs and new GM LS9 head gaskets ( Im pretty sure they fit the 5.3 ) but if not use GM MLS replacements. If you want to get more adventurous pull the crank and increase the top piston ring gap to around 25 thou

 

How does this sound like a head gasket to you guys? Don't open the rings up they're shot that's boost going past your rings into your crankcase pressurizing it which is blowing oil out your breathers. Sorry bud I don't think head gaskets will do **** for you.

 

Thanks guys, actually that was my first guess, but people said it's blowby but blow by isn't oil shooting out either. Good thing I have a spare 5.3 for now, and will probably build this one back up or get a 4.8, read they do better with boost

 

Smoke out of the breathers? Pull the dipstick and smell the oil on the end of it. I'll bet it smells like gasoline. This is blow-by. How much boost are you making?

 

"the exhaust is now blowing white smoke out the back after a pull"....

 

About 10psi maybe less, that's all I've seen so far but I haven't ran it much. It was very rich when tuning at home and I'm thinking we could have washed rings out. I really am not sure ok this one.... I just know it smokes bad after a pull and Will smoke from breathers at idle. Blows oil on boost pulls and vapors at idle...

 

but blow by isn't oil shooting out either.

Umm... that's basically the definition of blow by. The white smoke out the tailpipe could be coolant but I doubt it with your blow by problem. More likely that's also oil being blown out your exhaust, also a possibility is you now have too much pressure in your crankcase for your turbo to drain and it could be pushing oil past the seal into the turbine housing.

 

I have two vent hoses running from each valve cover to a bottle and one to the ground. What other ways could I reduce pressure on my crankcase to prevent this, if this is a possible problem?

 

That's probably sufficient for a healthy motor, im saying if your blowing past your rings that could be going on too. Smell your oil like mentioned above.

 

You guys are amazing. How about running a compression test, basic mechanics.